Liquid crystal display

ABSTRACT

A liquid crystal display includes: first and second gate lines disposed on the first substrate and which respectively transmit first and second gate signals; first, second and third data lines disposed on the first substrate; a first switching element connected to the first gate line and the first data line; a second switching element connected to the first gate line and the second data line; a third switching element connected to the second gate line and the second data line; a fourth switching element connected to the second gate line and the third data line; first and second pixel electrodes respectively connected to the first and second switching and which form a first liquid crystal capacitor; and third and fourth pixel electrodes respectively connected to the third and fourth switching elements and which form a second liquid crystal capacitor.

This application claims priority to Korean Patent Application No.10-2009-0047425, filed on May 29, 2009, and all the benefits accruingtherefrom under 35 U.S.C. §119, the content of which in its entirety isherein incorporated by reference.

BACKGROUND OF THE INVENTION

(a) Field of the Invention

The present invention relates to a liquid crystal display.

(b) Description of the Related Art

A liquid crystal display (“LCD”) is a widely used type of flat paneldisplay (“FPD”), and typically includes two display panels on whichfield generating electrodes, such as pixel electrodes and a commonelectrode, are disposed, and a liquid crystal layer interposed betweenthe two display panels. Voltages are applied to the field generatingelectrodes to generate an electric field in the liquid crystal layer.The electric field determines orientations of liquid crystal moleculesin the liquid crystal layer, and controls polarization of incident lightto display an image.

The LCD may further include switching elements connected to pixelelectrodes, and signal lines such as gate lines and data lines, forexample, which control the switching elements and apply voltages to thepixel electrodes.

The LCD typically receives an input image signal from an externalsource, e.g., a graphics controller, and the input image signal includesluminance information for each pixel, and the luminance informationincludes grayscale values. Each pixel receives the data voltagecorresponding to the luminance information. The data voltage is appliedto each pixel, and a difference between the data voltage and the commonvoltage is a pixel voltage. Each pixel thereby displays a luminancerepresenting a gray level of the image signal based on the pixelvoltage. A range of the pixel voltage applied to the liquid crystaldisplay may vary based on a driver.

In a conventional LCD, the driver of the liquid crystal display may bedisposed on the display panel as an integrated circuit (“IC”) chip, ordisposed on a flexible circuit film and attached to the display panel.However, the IC chip increases the manufacturing cost of the liquidcrystal display. Particularly, the cost of the driver of the liquidcrystal display is substantially increased as the number of data linesapplying the data voltage is increased.

BRIEF SUMMARY OF THE INVENTION

Exemplary embodiments of the present invention provide a liquid crystaldisplay (“LCD”) having advantages that include, but are not limited to,increased contrast ratio and viewing angle, improved response speed ofliquid crystal molecules, and reduced cost of the driver of the liquidcrystal display by decreasing a required number of data lines.

An exemplary embodiment of a liquid crystal includes: a first substrateand a second substrate disposed opposite the first substrate; a liquidcrystal layer interposed between the first and second substrates andincluding liquid crystal molecules; a first gate line disposed on thefirst substrate and which transmits a first gate signal; a second gateline disposed on the first substrate and which transmits a second gatesignal; a first data line disposed on the first substrate, a second dataline disposed on the first substrate, and a third data line disposed onthe first substrate; a first switching element connected to the firstgate line and the first data line; a second switching element connectedto the first gate line and the second data line; a third switchingelement connected to the second gate line and the second data line; afourth switching element connected to the second gate line and the thirddata line; a first pixel electrode connected to the first switchingelement; a second pixel electrode connected to the second switchingelement and separated from the first pixel electrode; a third pixelelectrode connected to the third switching element; and a fourth pixelelectrode connected to the fourth switching element and separated fromthe third pixel electrode, where the first pixel electrode and thesecond pixel electrode form a first liquid crystal capacitor, and thethird pixel electrode and the fourth pixel electrode form a secondliquid crystal capacitor.

In an exemplary embodiment, the first pixel electrode may include firstbranches, the second pixel electrode may include second branches, andthe first branches of the first pixel electrode and the second branchesof the second pixel electrode may be alternately disposed on the firstsubstrate. The third pixel electrode may include third branches, thefourth pixel electrode may include fourth branches, and the thirdbranches of the third pixel electrode and the fourth branches of thefourth pixel electrode may be alternately disposed on the firstsubstrate.

In an exemplary embodiment, when the first gate line receives a gate onsignal, the first pixel electrode may receive a first data voltage fromthe first data line, the second pixel electrode may receive a seconddata voltage from the second data line, and a polarity of the first datavoltage with respect to a reference voltage may be opposite to apolarity of the second data voltage with respect to the referencevoltage.

In an exemplary embodiment, when the second gate line receives a gate-onsignal, the third pixel electrode may receive a third data voltage fromthe second data line, the fourth pixel electrode may receive a fourthdata voltage from the third data line, a polarity of the third datavoltage with respect to the reference voltage may be opposite to apolarity of the fourth data voltage with respect to the referencevoltage, and the polarity of the second data voltage may be the same asthe polarity of the third data voltage.

An exemplary embodiment of the liquid crystal display may furtherinclude: a third gate line disposed on the first substrate; a fourthgate line disposed on the first substrate; a fourth data line disposedon the first substrate, a fifth data line disposed on the firstsubstrate, and a sixth data line disposed on the first substrate; afifth switching element connected to the third gate line and the fourthdata line; a sixth switching element connected to the third gate lineand the fifth data line; a seventh switching element connected to thefourth gate line and the fifth data line; an eighth switching elementconnected to the fourth gate line and the sixth data line; a fifth pixelelectrode connected to the fifth switching element, a sixth pixelelectrode connected to the sixth switching element and separated fromthe fifth pixel electrode, and a seventh pixel electrode connected tothe seventh switching element, an eighth pixel electrode connected tothe eighth switching element and separated from the seventh pixelelectrode, where the third gate line may be connected to the first gateline and transmit the first gate signal, the fourth gate line may beconnected to the second gate line and transmit the second gate signal,the fifth pixel electrode and the sixth pixel electrode form a thirdliquid crystal capacitor, and the seventh pixel electrode and the eighthpixel electrode may form a fourth liquid crystal capacitor.

In an exemplary embodiment, the first data line and the fourth data linemay be disposed substantially adjacent to each other, the second dataline and the fifth data line may be disposed substantially adjacent toeach other, and the third data line and the sixth data line may bedisposed substantially adjacent to each other.

In an exemplary embodiment, the fifth may include fifth branches, thesixth pixel electrode may include sixth branches, and the fifth branchesof the fifth pixel electrode and the sixth branches of the sixth pixelelectrode may be alternately disposed on the first substrate. Theseventh pixel electrode may include seventh branches, the eighth pixelelectrode may include eighth branches, and the seventh branches theseventh pixel electrode and the eighth branches of the eighth pixelelectrode may be alternately disposed on the first substrate.

An exemplary embodiment of the liquid crystal display may furtherinclude a first storage capacitor connected to the first switchingelement and a second storage capacitor connected to the second switchingelement and separated from the first storage capacitor.

An exemplary embodiment of the liquid crystal display may furtherinclude a capacitive electrode connected to the first pixel electrodeand which overlaps the second pixel electrode with an insulating layerdisposed therebetween, and the capacitive electrode and the second pixelelectrode form a storage capacitor.

An alternative exemplary embodiment of the liquid crystal displayincludes: a first substrate and a second substrate facing disposedopposite the first substrate; a liquid crystal layer interposed betweenthe first and second substrates and including liquid crystal molecules;a first gate line disposed on the first substrate and which transmits afirst gate signal; a second gate line disposed on the first substrateand which transmits a second gate signal; a third gate line disposed onthe first substrate and which transmits a third gate signal; a firstdata line disposed on the first substrate and a second data linedisposed on the first substrate; a first switching element connected tothe first gate line and the first data line; a second switching elementconnected to the second gate line and the second data line; a thirdswitching element connected to the third gate line and an outputterminal of the second switching element; and a first pixel electrodeconnected to the first switching element and a second pixel electrodeconnected to the second switching element and separated from the firstpixel electrode, where an input terminal of the third switching elementis connected to the output terminal of the second switching element, anoutput terminal of the third switching element is connected to thesecond pixel electrode, and the first pixel electrode and the secondpixel electrode form a first liquid crystal capacitor.

In an exemplary embodiment, when the first gate line receives a gate-onsignal, the first pixel electrode may receive a first data voltage fromthe first data line and the third pixel electrode may receive a seconddata voltage from the second data line. When the second gate linereceive the gate-on signal, the second pixel electrode may receive athird data voltage from the second data line and the fourth pixelelectrode may receive a fourth data voltage from the third data line,the first data voltage and the second data voltage may have differentpolarities, and the second data voltage and the third data voltage mayhave different polarities.

In an exemplary embodiment, when the third gate line receives the gateon signal, the second data voltage may be transmitted through the thirdswitching element.

An exemplary embodiment of the liquid crystal display may furtherinclude: a fourth gate line disposed on the first substrate, a fifthgate line disposed on the first substrate, and a sixth gate linedisposed on the first substrate; a third data line disposed on the firstsubstrate and a fourth data line disposed on the first substrate; afourth switching element connected to the fourth gate line and the thirddata line; a fifth switching element connected to the fifth gate lineand the fourth data line; a sixth switching element connected to thesixth gate line and an output terminal of the fifth switching element;and a third pixel electrode connected to the fourth switching elementand a fourth pixel electrode connected to the fifth switching elementand separated from the third pixel electrode, where the fourth gate linemay be connected to the first gate line and transmit the first gatesignal, the fifth gate line may be connected to the second gate line andtransmit the second gate signal, the sixth gate line may be connected tothe third gate line and transmit the same gate signal, and the thirdpixel electrode and the fourth pixel electrode may form a second liquidcrystal capacitor.

In an exemplary embodiment, the first data line and the third data linemay be disposed substantially adjacent to each other, and the seconddata line and the fourth data line may be disposed substantiallyadjacent to each other.

An alternative exemplary embodiment of a liquid crystal displayincludes: a first substrate and a second substrate disposed opposite thefirst substrate; a liquid crystal layer interposed between the first andsecond substrates and including liquid crystal molecules; a first gateline disposed on the first substrate and which transmit a first gatesignal; a second gate line disposed on the first substrate and whichtransmits a second gate signal; a data line disposed on the firstsubstrate; a first switching element connected to the first gate lineand the data line; a second switching element connected to the secondgate line and the data line; a first pixel electrode connected to thefirst switching element; a second pixel electrode connected to thesecond switching element and separated from the first pixel electrode;and a step-up capacitor including a first capacitive electrode and asecond capacitive electrode connected to the first and second switchingelements, respectively, and which overlap each other with an insulatinglayer disposed therebetween, where the first pixel electrode and thesecond pixel electrode form a first liquid crystal capacitor.

In an exemplary embodiment, when the first gate line receives a gate-onsignal, the first pixel electrode and the first capacitive electrode mayreceive the first data voltage from the data line, when the second gateline receives the gate-on signal, the second pixel electrode and thesecond capacitive electrode may receives the second data voltage fromthe data line, and voltages of the first pixel electrode and the firstcapacitive electrode may be substantially increased.

An exemplary embodiment of the liquid crystal display may furtherinclude a third switching element including an input terminal connectedto the first gate line and an output terminal connected to the secondpixel electrode and the second capacitive electrode, and the inputterminal of the third switching element may receive a common voltage.

In an exemplary embodiment, when the first gate line receives thegate-on signal, the second pixel electrode and the second capacitiveelectrode may receive the common voltage through the third switchingelement.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other aspects, advantages and features of the presentinvention will become more apparent by describing in further detailexemplary embodiments thereof with reference to the accompanyingdrawings, in which:

FIG. 1 is a block diagram of an exemplary embodiment of a liquid crystaldisplay according to the present invention;

FIG. 2 is a schematic equivalent circuit diagram of an exemplaryembodiment of a pixel according to the present invention;

FIG. 3 is a partial cross-sectional view of an exemplary embodiment of aliquid crystal display according to the present invention;

FIG. 4 is a plan view illustrating a layout of an exemplary embodimentof pixel electrodes of a liquid crystal display according to the presentinvention;

FIG. 5 is a schematic circuit diagram of an exemplary embodiment of fourpixels of a liquid crystal display according to the present invention;

FIG. 6 is a signal timing diagram of an exemplary embodiment of waveforms of signals applied to one pixel of the liquid crystal display inFIG. 5;

FIG. 7 is a plan view illustrating a layout of an exemplary embodimentof four pixels of a liquid crystal display in FIG. 5;

FIG. 8 is a schematic circuit diagram of an alternative exemplaryembodiment of four pixels of a liquid crystal display according to thepresent invention;

FIG. 9 is a schematic circuit diagram of an exemplary embodiment of twopixels of a liquid crystal display according to the present invention;

FIG. 10 is a partial cross-sectional view of an exemplary embodiment ofa storage capacitor in a liquid crystal display according to the presentinvention;

FIG. 11 is a schematic circuit diagram of an exemplary embodiment of twopixels of a liquid crystal display according to the present invention;

FIG. 12 is a schematic circuit diagram of an alternative exemplaryembodiment of one pixel according to the present invention;

FIG. 13 is a schematic circuit diagram of another alternative exemplaryembodiment of one pixel in a liquid crystal display according to thepresent invention;

FIG. 14 is a signal timing diagram of an exemplary embodiment ofwaveforms of signals applied to the one pixel of the liquid crystaldisplay in FIG. 13; and

FIG. 15 is a schematic circuit diagram of an alternative exemplaryembodiment of one pixel in a liquid crystal display according to thepresent invention.

DETAILED DESCRIPTION OF THE INVENTION

The invention now will be described more fully hereinafter withreference to the accompanying drawings, in which various embodiments areshown. This invention may, however, be embodied in many different forms,and should not be construed as limited to the embodiments set forthherein. Rather, these embodiments are provided so that this disclosurewill be thorough and complete, and will fully convey the scope of theinvention to those skilled in the art. Like reference numerals refer tolike elements throughout.

It will be understood that when an element is referred to as being “on”another element, it can be directly on the other element or interveningelements may be present therebetween. In contrast, when an element isreferred to as being “directly on” another element, there are nointervening elements present. As used herein, the term “and/or” includesany and all combinations of one or more of the associated listed items.

It will be understood that, although the terms first, second, third etc.may be used herein to describe various elements, components, regions,layers and/or sections, these elements, components, regions, layersand/or sections should not be limited by these terms. These terms areonly used to distinguish one element, component, region, layer orsection from another element, component, region, layer or section. Thus,a first element, component, region, layer or section discussed belowcould be termed a second element, component, region, layer or sectionwithout departing from the teachings of the present invention.

The terminology used herein is for the purpose of describing particularembodiments only and is not intended to be limiting. As used herein, thesingular forms “a,” “an” and “the” are intended to include the pluralforms as well, unless the context clearly indicates otherwise. It willbe further understood that the terms “comprises” and/or “comprising,” or“includes” and/or “including” when used in this specification, specifythe presence of stated features, regions, integers, steps, operations,elements, and/or components, but do not preclude the presence oraddition of one or more other features, regions, integers, steps,operations, elements, components, and/or groups thereof.

Furthermore, relative terms, such as “lower” or “bottom” and “upper” or“top,” may be used herein to describe one element's relationship toanother element as illustrated in the Figures. It will be understoodthat relative terms are intended to encompass different orientations ofthe device in addition to the orientation depicted in the Figures. Forexample, if the device in one of the figures is turned over, elementsdescribed as being on the “lower” side of other elements would then beoriented on “upper” sides of the other elements. The exemplary term“lower,” can therefore, encompasses both an orientation of “lower” and“upper,” depending on the particular orientation of the figure.Similarly, if the device in one of the figures is turned over, elementsdescribed as “below” or “beneath” other elements would then be oriented“above” the other elements. The exemplary terms “below” or “beneath”can, therefore, encompass both an orientation of above and below.

Unless otherwise defined, all terms (including technical and scientificterms) used herein have the same meaning as commonly understood by oneof ordinary skill in the art to which this invention belongs. It will befurther understood that terms, such as those defined in commonly useddictionaries, should be interpreted as having a meaning that isconsistent with their meaning in the context of the relevant art and thepresent disclosure, and will not be interpreted in an idealized oroverly formal sense unless expressly so defined herein.

Exemplary embodiments are described herein with reference to crosssection illustrations that are schematic illustrations of idealizedembodiments. As such, variations from the shapes of the illustrations asa result, for example, of manufacturing techniques and/or tolerances,are to be expected. Thus, embodiments described herein should not beconstrued as limited to the particular shapes of regions as illustratedherein but are to include deviations in shapes that result, for example,from manufacturing. For example, a region illustrated or described asflat may, typically, have rough and/or nonlinear features. Moreover,sharp angles that are illustrated may be rounded. Thus, the regionsillustrated in the figures are schematic in nature and their shapes arenot intended to illustrate the precise shape of a region and are notintended to limit the scope of the present claims.

FIG. 1 is a block diagram of an exemplary embodiment of a liquid crystaldisplay according to the present invention, and FIG. 2 is a schematicequivalent circuit diagram of an exemplary embodiment of a pixelaccording to an exemplary embodiment of the present invention.

As shown in FIG. 1, the liquid crystal display includes a liquid crystalpanel assembly 300, a gate driver 400, a data driver 500, a gray voltagegenerator 800 and a signal controller 600.

As shown in FIG. 2, the liquid crystal panel assembly 300 includes alower panel 100 and an upper panel 200 disposed to, e.g., facing, thelower panel 100, and a liquid crystal layer 3 interposed between thelower panel 100 and the upper panel (hereinafter collectively referredto as “display panels 100 and 200).

The liquid crystal capacitor Clc includes a first pixel electrode PEaand a second pixel electrode PEb of the lower panel 100 as two terminalsthereof, and the liquid crystal layer 3 between the first pixelelectrode PEa and the second pixel electrode PEb may be a dielectric.The first pixel electrode PEa is connected to a first switching element(not shown in FIG. 2), and the second pixel electrode PEb is connectedto a second switching element (not shown). The first switching elementand the second switching element are connected to corresponding gatelines (not shown) and data lines (not shown).

The liquid crystal layer 3 has dielectric anisotropy, and liquid crystalmolecules of the liquid crystal layer 3 may be arranged such that theirlongitudinal axes are aligned substantially vertical to surfaces of thedisplay panels 100 and 200 when an electric field is not applied in theliquid crystal layer 3. The liquid crystal layer 3 may have positivedielectric anisotropy.

The first pixel electrode PEa and the second pixel electrode PEb may bedisposed on two different layers or on a same layer, and the liquidcrystal panel assembly may further include a common electrode (notshown) disposed on one panel of the lower panel 100 and the upper panel200. Separate electrodes (not shown) disposed on the lower panel 100 mayoverlap the first and second pixel electrodes PEa and PEb via aninsulator interposed therebetween, and thereby form a first storagecapacitor (not shown) and a second storage capacitor (not shown), whichassist the liquid crystal capacitor Clc.

In an exemplary embodiment, when a display panel displays colors, eachpixel PX may display one of primary colors (spatial division), or eachpixel PX may display primary colors in turn (temporal division). In anexemplary embodiment, the primary colors may be spatially or temporallysynthesized, and a predetermined color is thereby displayed. The primarycolors may be three primary colors, such as red, green and blue, forexample. In an exemplary embodiment, as shown in FIG. 2, each pixel PXmay include a color filter CF, corresponding to one of the primarycolors, disposed on the upper panel 200. In an alternative exemplaryembodiment, the color filter CF may be disposed on or below the firstand second pixel electrodes PEa and PEb of the lower panel 100.

In an exemplary embodiment, the liquid crystal panel assembly 300includes at least one polarizer (not shown) which provides lightpolarization.

An operation of a liquid crystal display according to an exemplaryembodiment of the present invention will be described hereafter.

FIG. 3 is a partial cross-sectional view of an exemplary embodiment of aliquid crystal display according to the present invention.

As shown in FIG. 2 and FIG. 3, when a data line connected to a pixel PXreceives a data voltage, the data voltage is applied to the pixel PXthrough the first and second switching elements turned on by the gatesignal. When the first and second switching elements turned on by thegate signal, the first pixel electrode PEa receives a first data voltagethrough the first switching element, and the second pixel electrode PEbreceives a second data voltage through the second switching element. Inan exemplary embodiment, two data voltages, e.g., the first data voltageand the second data voltage, applied to the first and second pixelelectrodes PEa and PEb, respectively, may be data voltages correspondingto a luminance to be displayed by the pixel PX, and may have oppositepolarities with respect to a reference voltage Vref.

The difference between the two data voltages applied to the first andsecond subpixels PXa and PXb may be a charged voltage of the liquidcrystal capacitors Clc, e.g., a pixel voltage. When a potentialdifference is generated between two terminals of the liquid crystalcapacitor Clc, as shown in FIG. 3, an electric field parallel to thesurfaces of the display panel 100 and 200 is generated in the liquidcrystal layer 3 between the first pixel electrode PEa and the secondpixel electrode PEb. When liquid crystal molecules 31 have positivedielectric anisotropy, the liquid crystal molecules 31 are arranged suchthat the longitudinal axes thereof are aligned to be parallel to adirection of the electric field, and inclination degrees of the liquidcrystal molecules 31 may vary based on a magnitude of the pixel voltage.When the liquid crystal molecules 31 are aligned as described above, theliquid crystal layer 3 is referred to as an electrically-induced opticalcompensation (“EOC”) mode liquid crystal layer. In an exemplaryembodiment, a degree of a change of polarization of light passingthrough the liquid crystal layer 3 may vary based on the inclinationdegree of the liquid crystal molecules 31. The change of thepolarization may change transmittance of the light by the polarizer, andthe pixel PX thereby displays a predetermined luminance.

In an exemplary embodiment, when one pixel PX receives the two datavoltages having opposite polarities with respect to the referencevoltage Vref, a driving voltage is substantially increased and aresponse speed and a transmittance of the liquid crystal molecule arethereby substantially increased. In an exemplary embodiment, when thepolarities of the two data voltages applied to one pixel PX are oppositeto each other, degradation of the display quality due to flicker issubstantially prevented under driving types such as a column inversionor a row inversion, for example, as the degradation is substantiallyprevented under a dot inversion.

In an exemplary embodiment, when the first and second switching elementsare turned off in one pixel PX, the two data voltages applied to thefirst and second pixel electrodes PEa and PEb are substantiallydecreased by a kickback voltage such that the charging voltage of thepixel PX is substantially maintained, and display characteristics of theliquid crystal display are thereby effectively improved.

A layout of an exemplary embodiment of the first and second pixelelectrodes PEa and PEb of a pixel PX of the liquid crystal panelassembly according to the present invention will be descried hereafter.FIG. 4 is a plan view of a layout of an exemplary embodiment of pixelelectrodes of a pixel of a liquid crystal display.

As shown in FIG. 4, an overall contour of the pixel electrodes PEincluding the first pixel electrode PEa and the second pixel electrodePEb has a quadrangle shape. The first pixel electrode PEa and the secondpixel electrode PEb are engaged with each other with a gap 91therebetween. The first and second pixel electrodes PEa and PEb,respectively, are substantially mirror symmetric with respect to animaginary transverse center line CL. The first pixel electrode PEaincludes a first upper region disposed above the imaginary transversecenter line CL and a first lower region disposed below the imaginarytransverse center line CL, and the second pixel electrode PEb includes asecond upper region disposed above the imaginary transverse center lineCL and a second lower region disposed below the imaginary transversecenter line CL.

The first pixel electrode PEa includes an upper projection, a lowerprojection, a first left longitudinal stem, a first transverse stemextending to a right direction from a center of the first leftlongitudinal stem, first upper branches and first lower branches. Thefirst upper branches disposed above the imaginary transverse center lineCL extend substantially obliquely in an upper right direction from thefirst left longitudinal stem and from the first transverse stem. Thefirst lower branches disposed below the imaginary transverse center lineCL extend substantially obliquely in a lower right direction from thefirst left longitudinal stem and the first transverse stem. An anglebetween the first upper and lower branches and the gate line 121 or anangle between the first upper and lower branches and the transversecenter line CL may be about 45 degrees.

The second pixel electrode PEb includes a middle projection, a secondright longitudinal stem, a second upper transverse stem, a second lowertransverse stem, second upper branches and second lower branches. Thesecond upper transverse stem and the second lower transverse stem extendsubstantially horizontally to a left direction from a lower end and anupper end of the longitudinal stem, respectively. The second upperbranches disposed above the imaginary transverse center line CL extendssubstantially obliquely in a lower left direction from the second rightlongitudinal stem or the second upper transverse stem. The second lowerbranches disposed below the imaginary transverse center line CL extendssubstantially obliquely in an upper left direction from the second rightlongitudinal stem or the second lower transverse stem. An angle betweenthe second upper and lower branches of the second pixel electrode PEband the gate line 121 or an angle between the second upper and lowerbranches of the second pixel electrode PEb and the imaginary transversecenter line CL may be about 45 degrees. An angle between the secondupper branches adjacent to the imaginary transverse center line CL andthe second lower branches adjacent to the imaginary transverse centerline CL may be about 90 degrees. [NOTE: It is not clear from the FIG. 4what specifically the “projections” of the first and second pixelelectrodes are. Please confirm that the first projections of the firstpixel electrode are projections at the ends of the first leftlongitudinal stem, and the second projection of the second pixelelectrode is the projection at the center of the second rightlongitudinal stem.]

The first upper and lower branches of the first subpixel electrode PEaand the second upper and lower branches of the second subpixel electrodePEb are alternately disposed by engaging the upper and lower branches ofthe first subpixel electrodes PEa with the upper and lower branches ofthe second subpixel electrodes PEb, respectively, with a predeterminedgap 91 therebetween, and thereby formed in a pectinated pattern.

In an alternative exemplary embodiment, the first and second pixelelectrodes PEa and PEb of the pixel PX of the liquid crystal display maybe in a different shape in which at least a portions the first pixelelectrode PEa and at least a portion of the second pixel electrode PEbare alternately disposed in a same layer.

An arrangement and driving method of pixels and signal lines of anexemplary embodiment of a liquid crystal display according to thepresent invention will be described hereafter with reference to FIG. 5and FIG. 6. FIG. 5 is a schematic circuit diagram of an exemplaryembodiment of four pixels of the liquid crystal display according to thepresent invention, and FIG. 6 is a signal timing diagram illustrating anexemplary embodiment of wave forms of signals applied to one pixel ofthe liquid crystal display of FIG. 5.

Referring back to FIG. 2 and as shown in FIG. 5, a liquid crystaldisplay may include a first pixel PX(m, n) and a second pixel PX(m, n+1)adjacent to the first pixel PX(m, n) in a pixel row direction, a thirdpixel PX(m+1, n) and a fourth pixel PX(m+1 and n+1), respectively,adjacent to the first pixel PX(m, n) and the second pixel PX(m, n+1) ina pixel column direction, and signal lines Gi(a), Gi(b), Gi+1(a),Gi+1(b), Dj, Dj+1, and Dj+2 connected thereto. The signal lines Gi(a),Gi(b), Gi+1(a), Gi+1(b), Dj, Dj+1, and Dj+2 include pairs of gate lineswhich transmit gate signals (alternatively referred to as “scanningsignals”), for example, a i-th (where “i” is a natural number less thanor equal to “n”) pair of gate lines Gi(a) and Gi(b), and a (i+1)-th pairof gate lines Gi+1(a) and Gi+1(b), and data lines which transmit datavoltages including a j-th (where “j” is a natural number less than orequal to “m”) data line, e.g. a first data line Dj, a (j+1)-th dataline, e.g., a second data line Dj+1, and a (j+2)-th data line, e.g., athird data line Dj+2.

The first pixel PX(m, n) is connected to a first upper gate line Gi(a),which is one of the i-th pair of gate lines Gi(a) and Gi(b), the firstdata line Dj and the second data line Dj+1. The first pixel PX(m, n)includes a first switching element Qa connected to the first gate lineGi(a) and the first data line Dj, a second switching element Qbconnected to the first upper gate line Gi(a), and the second data lineDj+1, a liquid crystal capacitor Clc connected to the first and secondswitching elements Qa and Qb, and a first storage capacitor Csta and asecond storage capacitor Cstb connected to the liquid crystal capacitorClc. An alternative exemplary embodiment may not include the first andsecond storage capacitors Csta and Cstb. The first and second switchingelements Qa and Qb, may be three terminal elements, such as thin filmtransistors, for example. The first storage capacitor Csta may include acontrol terminal connected to the first upper gate line Gi(a), an inputterminal connected to the first data line Dj, and an output terminalconnected to the liquid crystal capacitor Clc and the first storagecapacitor Csta, and the second storage capacitor Cstb may include acontrol terminal connected to the first gate line Gi(a), an inputterminal connected to the second data line Dj+1, and a second outputterminal connected to the liquid crystal capacitor Clc and the secondstorage capacitor Cstb. The liquid crystal capacitor Clc includes thefirst pixel electrode PEa and the second pixel electrode PEb as twoterminals thereof, and the liquid crystal layer 3 between the firstpixel electrode and the second pixel electrode may be a dielectric. Thefirst pixel electrode PEa is connected to the first switching elementQa, and the second pixel electrode PEb is connected to the secondswitching element Qb.

The second pixel PX(m, n+1) adjacent to the first pixel PX(m, n) in thepixel row direction is connected to a first lower gate line Gi(b), whichis the other of the i-th pair of gate lines Gi(a) and Gi(b), the seconddata line and the third data line Dj+2. The second pixel PX(m, n+1)includes a first switching element Qa connected to the second gate lineGi(b) and the second data line Dj+1, a second switching element Qbconnected to the first lower gate line Gi(b) and the third data lineDj+2, a liquid crystal capacitor Clc connected to the first and secondswitching elements Qa and Qb, and a first storage capacitor Csta and asecond storage capacitor Cstb connected to the liquid crystal capacitorClc.

The third pixel PX(m+1, n) adjacent to the first pixel PX(m, n) in thepixel column direction is connected to the second upper gate lineGi+1(a), which is one of the (i+1)-th pair of gate lines Gi+1(a) andGi+1(b), the third data line Dj and the second data line Dj+1, andincludes a first switching elements Qa connected to the second upperGi+1(a) and the first data line Dj, a second switching element Qbconnected to the second upper gate line Gi+1(a) and the second data lineDj+1, a liquid crystal capacitor Clc connected to the first and secondswitching elements Qa and Qb, and a first storage capacitor Csta and asecond storage capacitor Cstb connected to the liquid crystal capacitorClc.

The fourth pixel PX(m+1, n+1) adjacent to the second pixel PX(m, n+1) inthe pixel column direction is connected to the second lower gate lineGi+1(b) which is the other of the (i+1)-th pair of gate lines Gi+1(a)and Gi+1(b), the second data line Dj+1, and the third data line Dj+2,and includes a first switching elements Qa connected to the second lowergate line Gi+1(b) and the second data line Dj+1 and a second switchingelement Qb connected to the second lower gate line Gi+1(b) and the thirddata line Dj+2, a liquid crystal capacitor Clc connected to the firstand second switching elements Qa and Qb, and a first storage capacitorCsta and a second storage capacitor Cstb connected to the liquid crystalcapacitor Clc.

The first pixel PX(m, n) and the second pixel PX(m, n+1) adjacent toeach other in the pixel row direction are both connected to the seconddata line Dj+1, and the third pixel PX(m+1, n) and the fourth pixelPX(m+1, n+1) are both connected to the second data line Dj+1.

As shown in FIG. 5 and FIG. 6, when the first upper gate line Gi(a) ofthe i-th pair of gate lines Gi(a) and Gi(b) receives a gate-on voltage,a first data voltage is applied to the first pixel PX(m, n) through thefirst and second switching elements Qa and Qb of the first pixel PX(m,n) that are turned on. In an exemplary embodiment, the first pixelelectrode PEa of the first pixel PX(m, n) receives the first datavoltage from the first data line Dj through the first switching elementQa of the first pixel PX(m, n), and the second pixel electrode PEb ofthe first pixel PX(m, n) receives a second data voltage from the seconddata line Dj+1 through the second switching element Qb of the firstpixel PX(m, n). When the first lower gate line Gi(b) of the i-th pair ofgate lines Gi(a) and Gi(b) receives the gate-on voltage, the second datavoltage is applied to the second pixel PX(m, n+1) through the first andsecond switching elements of the second pixel PX(m, n+1) that are turnedon. The first pixel electrode PEa of the second pixel PX(m, n+1)receives the second data voltage from the second data line Dj+1 throughthe first switching element Qa of the second pixel PX(m, n+1), and thesecond pixel electrode PEb of the second pixel PX(m, n+1) receives athird data voltage from the third data line Dj+2 through the secondswitching element Qb of the second pixel PX(m, n+1). Accordingly, a datavoltage to be transmitted to the second pixel electrode PEb of the firstpixel PX(m, n) is applied to the second data line Dj+1 during a timethat the first upper gate line Gi(a) receives the gate-on signal, and adata voltage to be transmitted to the first pixel electrode PEa of thesecond pixel PX(m, n+1) is applied to the second data line Dj+1 during atime that the first lower gate line Gi(b) receives the gate-on signal.

Voltages applied to the first and second pixel electrodes PEa and PEb ofthe first pixel PX(m, n) and the third pixel PX(m, n+1) are datavoltages corresponding to a luminance for the first pixel PX(m, n) andthe third pixel PX(m, n+1) to be respectively displayed, and haveopposite polarities with respect to the reference voltage Vref, forexample, a common voltage Vcom of a common electrode (not shown). In anexemplary embodiment, when a polarity of the first data voltage appliedto the first data line Dj is positive, a polarity of the second datavoltage applied to the second data line Dj+1 is negative and a polarityof the third data voltage applied to the third data line Dj+2 ispositive. When the polarity of the first data voltage applied to thefirst data line Dj is negative, the polarity of the second data voltageapplied to the second data line Dj+1 is positive and the polarity of thethird data voltage applied to the third data line Dj+2 is negative. Asdescribed above, the data lines of an exemplary embodiment of a liquidcrystal display according to the present invention may be driven with acolumn inversion.

In a conventional liquid crystal display, two pixels adjacent to eachother in the pixel row direction are connected to one gate line and fourdifferent data lines. That is, the first and second switching elementsconnected to the first and second pixel electrodes of each of the twopixels are connected to a same gate line, but they are connected todifferent data lines such that they receive the data voltages throughthe different data lines.

In an exemplary embodiment of a liquid crystal display according to thepresent invention, two pixels of the liquid crystal display adjacent toeach other in the pixel row direction are respectively connected to onegate line of a pair of gate lines and the other gate line of the pair ofgate lines, and connected to three data lines by sharing a middle dataline of the three data lines disposed in a middle portion of the twopixels adjacent to the two pixels. Accordingly, a number of data linesis reduced, and the cost of the driver of the liquid crystal display isthereby substantially reduced. In an exemplary embodiment, gate linesare disposed in pairs, and a number of gate lines is therebysubstantially increased, however gate signals are gate on/off signals,and an operation of a gate driver is thereby simplified, while themanufacturing cost is reduced.

An exemplary embodiment of the pixel of the liquid crystal display shownin FIG. 5 will be described hereafter with reference to FIG. 7. FIG. 7is a plan view illustrating a layout of an exemplary embodiment of fourpixels of the liquid crystal display shown in FIG. 5.

Referring back to FIG. 5 and as shown in FIG. 7, an exemplary embodimentof the liquid crystal display includes the first pixel PX(m, n) and thesecond pixel PX(m, n+1), the third pixel PX (m+1, n) and the fourthpixel PX (m+1, n+1) respectively adjacent to the first pixel PX(m, n)and the second pixel PX(m, n+1) in the pixel column direction, pairs ofgate lines, for example, a pair of gate lines including a first uppergate line 121 a 1 and a first lower gate line 121 b 1, and a pair ofgate lines including a second upper gate line 121 a 2 and a second lowergate line 121 b 2, and data lines, for example, a first data line 171 a,a second data line 171 b and a third data line 171 c connected thereto.Each of the first pixel PX(m, n), the second pixel PX(m, n+1), the thirdpixel PX(m+1, n), and the fourth pixel PX(m+1, n+1) includes a firstpixel electrode 191 a and a second pixel electrode 191 b connected to afirst switching element and a second switching element, respectively.The first switching element and the second switching element may bethree terminal elements such as thin film transistors, for example. Thefirst switching element and the second switching element, respectively,include control electrodes, e.g., a first gate electrode 124 a and asecond gate electrode 124 b, input electrodes, e.g., a first sourceelectrode 173 a and a second source electrode 173 b, and outputelectrodes, e.g., a drain electrode 175 a and a second drain electrode175 b. The control electrodes of the first and second switching elementsare respectively connected to one line and the other line of the pair ofgate lines 121 a and 121 b, the input electrodes of the first and secondswitching elements are respectively connected to one line and anotherline of the data lines 171 a, 171 b and 171 c, and the output electrodesof the first and second switching elements are respectively connected tothe first pixel electrode 191 a and the second pixel electrode 191 bthrough a first contact hole 185 a and a second contact hole 185 b. Thefirst pixel electrode 191 a and the second pixel electrode 191 b may besubstantially alternately disposed on a same layer.

In an exemplary embodiment, the liquid crystal display includes astorage electrode line 131 and storage electrodes 135 a and 135 b, andthe storage electrodes 135 a and 135 b overlap the first pixel electrode191 a and the second pixel electrode 191 b thereby forming storagecapacitors.

An alternative exemplary embodiment of an arrangement and driving methodof pixels and signal lines of an exemplary embodiment of a liquidcrystal display according to the present invention will be describedhereafter with reference to FIG. 2 and FIG. 8. FIG. 8 is a schematiccircuit diagram of an alternative exemplary embodiment of four pixels ofa liquid crystal display according to the present invention.

As shown in FIG. 8, the liquid crystal display includes a first pixelPX(m, n) and a second pixel PX(m, n+1) adjacent to the first pixel PX(m,n) in the pixel row direction, a third pixel PX(m+1, n) and a fourthpixel PX(m+1, n+1) respectively adjacent to the first pixel PX(m, n) andthe second pixel PX(m, n+1) in the pixel column direction, gate linesconnected thereto, for example, a first gate line Gi and a second gateline Gi+1, and pairs of data lines connected thereto, for example, afirst pair of data lines Dj and Dj', a second pair of data lines Dj+1and Dj+1′, and a third pairs of data lines Dj+2 and Dj+2′.

The first gate line Gi including a first upper line and a first lowerline and the second gate line Gi+1 including a second upper line andsecond lower line are disposed along the pixel column direction. Thefirst pair of data lines Dj and Dj′ including a first data line Dj and asecond data line Dj′, the second pair of data lines Dj+1 and Dj+1′including a first data line Dj+1 and a second data line Dj+1′, and thethird pair of data lines Dj+2 and Dj+2′ including a first data line Dj+2and a second data line Dj+2′ are disposed along the pixel row direction.

A control terminal of the first switching element Qa of the first pixeland a control terminal of the second switching element Qb of the firstpixel respectively connected to the first pixel electrode PEa and thesecond pixel electrode PEb of the first pixel PX(m, n) are connected thefirst upper line of the i-th gate line, e.g., the first gate line Gi,and an input terminal of the first switching element Qa and an inputterminal of the second switching element Qb are respectively connectedto one data line of the j-th pair of data lines, e.g., the second dataline Dj′ of the first pair of data lines Dj and Dj′, and one data lineof the (j+1)-th pair of data lines, e.g., the second data line Dj+1′ ofthe second pair of data lines Dj+1 and Dj+1′.

A control terminal of the first switching element Qa of the second pixeland a control terminal of the second switching element Qb of the secondpixel, respectively connected to the first pixel electrode PEa and thesecond pixel electrode PEb of the second pixel PX(m, n+1) adjacent tothe first pixel PX(m, n) in the pixel row direction, are connected to anupper line of the (i+1)-th gate line, e.g., the second upper line of thesecond gate line Gi+1, and an input terminal of the first switchingelement Qa of the first pixel and an input terminal of the secondswitching element Qb of the first pixel are respectively connected toone data line of the (j+1)-th pair of data lines, e.g., the second dataline Dj+1′ of the second pair of data lines Dj+1 and Dj+1′, and one dataline of the (j+2)-th pair of data lines, e.g., the second data lineDj+2′ of the third pair of data lines Dj+2 and Dj+2′.

A control terminal of the first switching elements Qa of the third pixeland a control terminal of the second switching element Qb of the thirdpixel, respectively connected to the first pixel electrode PEa and thesecond pixel electrode PEb of the third pixel PX(m+1, n) adjacent to thefirst pixel PX(m, n) in the pixel column direction, are connected to alower line of the i-th gate line, e.g., the first lower line of thefirst gate line Gi, and an input terminal of the first switching elementof the third pixel and an input terminal of the second switching elementof the third pixel are respectively connected to one data line of thej-th pair of data lines, e.g., the first data line Dj of the first pairof data lines Dj and Dj′ and one data line of the (j+1)-th pair of datalines, e.g., the second data line Dj+1′ of the second pair of data linesDj+1 and Dj+1′.

A control terminal of the first switching element of the fourth pixeland a control terminal of the second switching element Qb of the fourthpixel, respectively connected to the first pixel electrode PEa and thesecond pixel electrode PEb of the fourth pixel PX(m+1, n+1) adjacent tothe second pixel PX(m, n+1) in the pixel column direction and the thirdpixel PX(m+1, n) in the pixel row direction, are connected to the secondbranch of the (i+1)-th gate line, e.g., the second lower line of thesecond gate line Gi+1, and an input terminal of the first switchingelement of the fourth pixel and an input terminal of the secondswitching element Qb of the fourth pixel are respectively connected toone data line of the (j+1)-th pair of data lines, e.g., the first dataline Dj+1 of the second pair of data lines Dj+1 and Dj+1′ and one dataline of the (j+2)-th pair of data lines, e.g., the first data line Dj+2of the third pair of data lines Dj+2 and Dj+2′. As described above, thefirst pixel PX(m, n) and the second pixel PX(m, n+1) adjacent to eachother in the pixel row direction are connected to one data line, e.g.,the second data line Dj+1′ of the second pair of data lines Dj+1 andDj+1′, and the third pixel PX(m+1, n) and the fourth pixel PX(m+1, n+1)adjacent to each other in the pixel row direction are connected to onedata line, e.g., the first data line Dj+1 of the second pair of datalines Dj+1 and Dj+1′, in an exemplary embodiment of the liquid crystaldisplay. In an exemplary embodiment, the first pixel PX(m, n) and thethird pixel PX(m+1, n) adjacent to each other in the pixel columndirection are respectively connected to an upper line and a lower lineof one gate line, e.g., the first upper line and the first lower line ofthe first gate line Gi and thereby receives gate on/off voltages throughthe one gate line, e.g., the first gate line Gi, and the second pixelPX(m, n+1) and the fourth pixel PX(m+1, n+1) adjacent to each other inthe pixel column direction are respectively connected to an upper lineand a lower line of one gate line, e.g., the second upper line and thesecond lower line of the second gate line Gi+1 and thereby receives thegate on/off voltages through the one gate line, e.g., the second gateline Gi+1. Accordingly, the number of data lines and the number of gatelines are reduced, and the cost of the driver of the liquid crystaldisplay is thereby substantially reduced and the driving speed isthereby increased.

An alternative exemplary embodiment of an arrangement of pixels andsignal lines of a liquid crystal display according to the presentinvention will be described hereafter with reference to FIG. 9. FIG. 9is a schematic circuit diagram of an exemplary embodiment of twoneighboring pixels of a liquid crystal display according to the presentinvention.

An arrangement of an exemplary embodiment of pixels and signal lines ofthe liquid crystal display shown in FIG. 9 is substantially similar tothe arrangement of pixels and signal lines of an exemplary embodimentshown in FIG. 5. In an alternative exemplary embodiment, the first pixelPX(m, n) is connected to the first upper gate line Gi(a) of the i-thpair of gate lines Gi(a) and Gi(b), the first data line Dj and thesecond data line Dj+1, and the second pixel PX(m, n+1) adjacent to thefirst pixel PX(m, n) in the pixel row direction is connected to thefirst lower gate line Gi(b) of the i-th pair of gate lines Gi(a) andGi(b), the second data line Dj+1 and the third data line Dj+2. The firstpixel PX(m, n) and the second pixel PX(m, n+1) adjacent to each other inthe pixel row direction are connected to the middle data line of thethree data line, e.g., the second data line Dj+1.

In an alternative exemplary embodiment, as show in FIG. 5, two terminalsof a storage capacitor Cst of a pixel are connected to an outputterminal of a first switching element Qa of the pixel and a secondswitching element Qb of the pixel.

FIG. 10 is a partial cross-sectional view of an exemplary embodiment ofa storage capacitor Cst in a liquid crystal display according to thepresent invention.

As shown in FIG. 10, a first pixel electrode PEa of a pixel is connectedto a storage capacitance electrode 178 through a contact hole 186, and avoltage that the first pixel electrode PEa receives is therebytransmitted to the storage capacitance electrode 178. The storagecapacitance electrode 178 overlaps the second pixel electrode PEb via aninsulating layer 180, and the storage capacitance electrode 178 and thesecond pixel electrode PEb thereby form the storage capacitor Cst.

An exemplary embodiment of an arrangement of pixels and signal lines,and a driving method of a liquid crystal display will be describedhereafter with reference to FIG. 11 and FIG. 2. FIG. 11 is a schematiccircuit diagram of an exemplary embodiment of two pixels of a liquidcrystal display according to the present invention.

Referring back to FIG. 2 and as shown in FIG. 11, an exemplaryembodiment of the liquid crystal display includes the first pixel PX(m,n) and the second pixel PX(m, n+1) adjacent to each other in the pixelrow direction, and gate lines connected thereto, e.g., a first gate lineGi, a second gate line Gi+1, and a third gate line Gi+2, and data linesconnected thereto, e.g., a first data line Dj, a second data line Dj+1,and a third data line Dj+2.

The first pixel PX(m, n) includes a first switching element Qa connectedto the i-th gate line, e.g., the first gate line Gi, and the j-th dataline, e.g., the first data line Dj, a second switching element Qbconnected to the (i+1)-th gate line, e.g., the second gate line Gi+1,and the (j+1)-th data line, e.g., the second data line Dj+1, a firststorage capacitor Csta connected to the first switching element Qa ofthe first pixel and a second storage capacitor Cstb connected to thesecond switching element Qb of the first pixel. The first pixel PX(m, n)further includes a third switching element Qc connected to the (i+2)-thgate line, e.g., the third gate line Gi+2, and an output terminal of thesecond switching element Qb of the first pixel.

The first pixel electrode PEa of the first pixel is connected to thefirst switching element Qa of the first pixel, and the second pixelelectrode PEb of the first pixel is connected to the second switchingelement Qb of the first pixel through the third switching element Qc ofthe first pixel.

The second pixel PX(m, n+1) adjacent to the first pixel PX(m, n) in thepixel row direction includes a first switching element Qa connected tothe i-th gate line, e.g., the first gate line Gi, and the (j+1)-th dataline, e.g., the second data line Dj+1, a second switching element Qbconnected to the (i+1)-th gate line, e.g., the second gate line Gi+1,and the (j+2)-th data line, e.g., the third data line Dj+2, and a firststorage capacitor Csta connected to the first switching element Qa ofthe second pixel and a second storage capacitor Cstb connected to asecond switching element Qb of the second pixel. In an exemplaryembodiment, the second pixel PX(m, n+1) further includes a thirdswitching element Qc connected to the (i+2)-th gate line, e.g., thethird gate line Gi+2, and to an output terminal of the second switchingelement Qb of the second pixel.

The first pixel PX(m, n) and the second pixel PX(m, n+1) adjacent toeach other in the pixel row direction are connected to the (j+1)-th dataline, e.g., the second data line Dj+1.

When the first gate line Gi receives a gate-on voltage, a first datavoltage and a second data voltage are respectively applied to the firstpixel PX(m, n) through the first switching element Qa of the first pixelthat is thereby turned on and to the second pixel PX(m, n+1) through thefirst switching element Qa of the second pixel that is thereby turnedon. That is, the first pixel electrode PEa of the first pixel PX(m, n)receives the first data voltage from the first data line Dj through thefirst switching element Qa of the first pixel and a point A of the firstpixel thereby receives the first data voltage, and the first pixelelectrode PEa of the second pixel PX(m, n+1) receives the second datavoltage from the second data line Dj+1 through the first switchingelement Qa of the second pixel and a point A of the second pixel therebyreceives the second data voltage.

When the first gate line Gi receives a gate-off voltage and the secondgate line Gi+1 receives the gate-on voltage, the point A of the firstpixel and the point A of the second pixel are floated, and the firstdata voltage is applied to the first pixel PX(m, n) through the secondswitching element of the first pixel that is thereby turned on, and thesecond data voltage is applied to the second pixel PX(m, n+1) throughthe second switching element of the second pixel that is thereby turnedon. That is, the second pixel electrode PEb of the first pixel PX(m, n)and the second pixel electrode PEb of the second pixel PX(m, n+1)respectively receive the second data voltages from the second data lineDj+1 through the second switching element Qb of the first pixel and thethird data voltage from the third data line Dj+2 through the secondswitching element Qb of the second pixel.

When the second gate line Gi+1 receives the gate-off voltage and thethird gate line Gi+2 receives the gate-on voltage, the output terminalof the second switching element Qb of the first pixel and the outputterminal of the second switching element Qb of the second pixel arefloated, and the third switching element Qc of the first pixel and thethird switching element Qc of the second pixel are turned-on, and thefirst data voltage and second data voltage respectively charged andapplied to the second pixel electrode PEb of the first pixel and to thesecond pixel electrode PEb of the second pixel are respectivelytransmitted to a point B of the first pixel through the third switchingelement Qc of the first pixel and to a point B of the second pixelthrough the third switching element Qc of the second pixel. Accordingly,voltages of predetermined magnitudes are charged between the point A andthe point B of the first pixel forming two terminals of the liquidcrystal capacitor Clc of the first pixel and between the point A and thepoint B of the second pixels forming two terminals of the liquid crystalcapacitor Clc of the second pixels, respectively. In an exemplaryembodiment, data voltages respectively applied to the two terminals ofthe liquid crystal capacitor Clc of the first and second pixel maycorrespond to luminances of the first pixel PX(m, n) and the secondpixel PX(m, n+1) to be displayed, and have opposite polarities withrespect to the common voltage Vcom. In an exemplary embodiment, datavoltages applied to the first and second pixel electrodes PEa and PE ofthe first pixel and the first and second pixel electrodes PEa and PE ofthe second pixel may correspond to luminances of the pixel PX(m, n) andthe second pixel PX(m, n+1) to be displayed and have opposite polaritieswith respect to the reference electrode Vref. When the first datavoltage applied to the first data line Dj is positive, the second datavoltage applied to the second data line Dj+1 is negative and the thirddata voltage applied to the third data line Dj+2 is positive, and whenthe first data voltage applied to the first data line Dj is negative,the second data voltage applied to the second data line Dj+1 is positiveand the third data voltage applied to the third data line Dj+2 isnegative. As described above, the data lines of an exemplary embodimentof the liquid crystal display according to the present invention may bedriven with a column inversion.

In a conventional liquid crystal display, when one terminal of a liquidcrystal capacitor of the conventional liquid crystal display has beencharged and thereby floated with one voltage, and the other terminal ofthe liquid crystal capacitor is being charged with another voltagehaving polarity opposite to a polarity of the one voltage, it isdifficult for the liquid crystal capacitor of the conventional liquidcrystal display to be charged with a predetermined magnitude. However,in an exemplary embodiment of the liquid crystal display according tothe present invention, for example, the first and second data voltagesrespectively applied to the first and second pixel electrodes PEa andPEb of the first pixel through the first and second switching elementsQa and Qb of the first pixel during respective gate-on times is chargedto the liquid crystal capacitor Clc of the first pixel through theoutput terminal of the first and second switching elements Qa and Qb ofthe first pixel that have been floated during a gate-off time.Accordingly, the liquid crystal capacitor Clc of the first pixel may becharged when the two terminals of the liquid crystal capacitor Clc arefloated, and the first and second data voltages having oppositepolarities may be charged with a predetermined magnitude.

An arrangement and driving method of signal lines and pixels of anexemplary embodiment of a liquid crystal display will be describedhereafter with reference to FIG. 2 and FIG. 12. FIG. 12 is a schematiccircuit diagram of an exemplary embodiment of a pixel of a liquidcrystal display according to the present invention.

As shown in FIG. 12, an exemplary embodiment of the liquid crystaldisplay includes a first pixel PX(m) and a second pixel PX m+1 adjacentto each other in the pixel column direction, and gate lines, e.g., afirst gate line Gi, a second gate line Gi+1, and a third gate line Gi+2,and pairs of data lines, e.g., a first pair of data lines Dj and Dj′ anda second pair of data lines Dj+1, and Dj+1′ connected thereto.

The first gate line Gi including a first upper line and a first lowerline, the second gate line Gi+1 including a second upper line and asecond lower line, and the third gate line Gi+2 including a third upperline and a third lower line are disposed along the pixel columndirection. The first pair of data lines Dj and Dj′ including a firstdata line Dj and a second data line Dj′, and the second pair of datalines Dj+1 and Dj+1′ including a first data Dj+1 and a second data lineDj+1′, are disposed along the pixel row.

The control terminal of the first switching element Qa of the firstpixel PX(m) connected to the first pixel electrode PEa of the firstpixel PX(m) is connected to the first upper line of the first gate lineGi, and the input terminal thereof is connected to one data line of thej-th pair of data lines, e.g., the second data line Dj′ of the firstpair of data lines Dj and Dj′. The control terminal of the secondswitching element Qb of the first pixel PX(m) connected to the secondpixel electrode PEb of the first pixel PX(m) is connected to the secondupper line of the second gate line Gi+1, and the input terminal thereofis connected to one data line of the (j+1)-th pair of data lines, e.g.,the second data line Dj+1′ of the second pair of data lines Dj+1 andDj+1′. The input terminal of the third switching element Qc of the firstpixel PX(m) connected to the output terminal of the second switchingelement Qb of the first pixel PX(m) is connected to the third upper lineof the third gate line Gi+2.

The control terminal of the first switching element Qa of the secondpixel PX(m+1) connected to the first pixel electrode PEa of the secondpixel PX(m+1) is connected to the first lower line of the first gateline Gi, and the input terminal thereof is connected to one data line ofthe j-th pair of data lines, e.g. the first data line Dj of the firstpair of data lines Dj and Dj′. The control terminal of the secondswitching element Qb of the second pixel PX(m+1) connected to the secondpixel electrode PEb of the second pixel PX(m+1) is connected to thesecond lower line of the second gate line Gi+1, and the input terminalthereof is connected to one data line of the (j+1)-th pair of datalines, e.g., the first data line Dj+1 of the second pair of data linesDj+1 and Dj+1′. The input terminal of the third switching element Qc ofthe second pixel PX(m+1) connected to the output terminal of the secondswitching element Qb of the second pixel PX(m+1) is connected to thethird lower line of the third gate line Gi+2.

As described above, in an exemplary embodiment of a liquid crystaldisplay, the control terminal of the first switching elements Qa of thefirst pixel PX(m) connected to the first pixel electrode PEa of thefirst pixel PX(m) and the control terminal of the first switchingelement Qa of the second pixel PX(m+1) connected to the first pixelelectrode PEa of the second pixel PX(m+1) adjacent to the first pixelPX(m) in the pixel column direction are respectively connected to thefirst upper line and the first lower line of the first gate line Gi, andthereby receive the gate on/off voltages from one gate line, e.g., thefirst gate line Gi. The control terminal of the second switching elementQb of the first pixel PX(m) and the control terminal of the secondswitching element Qb of the second pixel PX(m+1) are respectivelyconnected to the second upper line and the second lower line of the samegate line Gi+1, and thereby receive the gate on/off voltages from onegate line, e.g., the second gate line Gi+1. The input terminal of thethird switching element Qc of the first pixel (PX(m) connected to theoutput terminal of the second switching element Qb of the first pixelPX(m) and the input terminal of the third switching element Qc of thesecond pixel PX(m+1) connected to the output terminal of the secondswitching element Qb of the second pixel PX(m+1) are respectivelyconnected to the third upper line and the third lower line of the thirdgate line Gi+2, and thereby receive the gate on/off voltages from onegate line, e.g., the third gate line Gi+2. Accordingly, the drivingspeed is substantially increased.

An arrangement and a driving method of pixels and signal lines of anexemplary embodiment of a liquid crystal display will be describedhereafter with reference to FIG. 2, FIG. 13 and FIG. 14.

FIG. 13 is a schematic circuit diagram of an exemplary embodiment of onepixel in a liquid crystal display according to the present invention,and FIG. 14 is a signal timing diagram illustrating an exemplaryembodiment of waveforms of a signal applied to the one pixel of theliquid crystal display in FIG. 13.

Referring back to FIG. 2 and as shown in FIG. 13, an exemplaryembodiment of a liquid crystal display includes the first switchingelement Qa connected to the first pixel electrode PEa of the pixel PX,the second switching element Qb connected to the second pixel electrodePEb of the pixel PX, gate lines including a first gate line Gi and asecond gate line Gi+1, and a data line Dj. In an exemplary embodiment,the liquid crystal display includes the liquid crystal capacitor Clc anda step-up capacitor Cb connected to the first and second switchingelements Qa and Qb. The control terminal of the first switching elementQa is connected to the first gate line Gi, and the input terminalthereof is connected to the data line Dj. The control terminal of thesecond switching element Qb is connected to the second gate line Gi+1,and the input terminal thereof is connected to the data line Dj. Theoutput terminal of the first switching element Qa and The outputterminals of second switching element Qb are connected to the liquidcrystal capacitor Clc and the step-up capacitor Cb. Two terminals of thestep-up capacitor Qb are connected to the first switching element Qa andthe second switching element Qb.

A driving method of an exemplary embodiment of a liquid crystal displayin FIG. 13 will be described hereafter with reference to FIG. 14.

Referring back to FIG. 13 and as shown in FIG. 14, when the first gateline Gi receives the gate-on signal and the first switching element Qais thereby turned on, the first pixel electrode PEa receives one datavoltage from the data line Dj and a point A is charged with the one datavoltage.

When the first gate line Gi receives a gate-off signal, the second gateline Gi+1 receives a gate-on signal, and the second switching element Qbis thereby turned on, the second pixel electrode PEb receives other datavoltage through the data line Dj, and a point B is charged with theother data voltage. When a voltage of the point A Va is increased, avoltage of the point B Vb is thereby increased, and a voltage chargedbetween the two terminals of the liquid crystal capacitor Clc connectedto the point A and the point B is thereby changed and a magnitude of thecharging voltage is thereby varied based on a capacity of the step-upcapacitor Cb. Accordingly, by changing a capacity of the step-upcapacitor Cb, the voltage charged to the liquid crystal capacitor Clcwhen the pixel receives two gate-on signals, is changed to have apredetermined magnitude.

In an exemplary embodiment of a the liquid crystal display, themagnitude of the voltage charged to the liquid crystal capacitor may bechanged by using two gate lines, one data line, and a step-up capacitor.Accordingly, compared to a liquid crystal display driven with one gateline and two data lines, a number of data lines is reduced, and the costof the driver of the liquid crystal display is thereby substantiallyreduced.

Next, signal lines and a pixel arrangement of a liquid crystal displayaccording to another exemplary embodiment of the present invention willbe described with reference to FIG. 15. FIG. 15 is a schematic circuitdiagram of an alternative exemplary embodiment of one pixel of a liquidcrystal display according to another exemplary embodiment of the presentinvention.

As shown in FIG. 15, an arrangement of a pixel and signal lines of anexemplary embodiment of the liquid crystal display is substantiallysimilar to the liquid crystal display in FIG. 13 except for a fourthswitching element Qd connected to the first gate line Gi and the point Bof the step-up capacitor Cb. The control terminal of the fourthswitching element Qd is connected to the first gate line Gi, and theinput terminal thereof is connected to a common voltage point Vcom.Accordingly, when the first gate line Gi receives the gate-on signalsuch that the first pixel electrode PEa of the pixel PX receives a datavoltage, the point B of the step-up capacitor Cb and one terminal of theliquid crystal capacitor Clc are changed with the common voltage Vcom.The point B of the step-up capacitor Cb and the one terminal of theliquid crystal capacitor Clc is refreshed by being charged with thecommon voltage Vcom which is the reference voltage to the point B of thestep-up capacitor Cb and the one terminal of the liquid crystalcapacitor Clc, and thereby minimize an influence of the voltages chargedduring a previous frame to the point B of the step-up capacitor Cb andthe one terminal of the liquid crystal capacitor Clc.

According to exemplary embodiments of the present invention as describedherein provide advantages which include, but are not limited to, a highcontrast ratio and a wide viewing angle, fast response speed of theliquid crystal, and a low manufacturing cost by substantially reducingnumber of signal lines in a liquid crystal display.

The present invention should not be construed as being limited to theexemplary embodiments set forth herein. Rather, these exemplaryembodiments are provided so that this disclosure will be thorough andcomplete and will fully convey the concept of the present invention tothose skilled in the art.

While the present invention has been particularly shown and describedwith reference to exemplary embodiments thereof, it will be understoodby those of ordinary skill in the art that various changes in form anddetails may be made therein without departing from the spirit or scopeof the present invention as defined by the following claims.

1. A liquid crystal display comprising: a first substrate; a secondsubstrate disposed opposite the first substrate; a liquid crystal layerinterposed between the first and second substrates and including liquidcrystal molecules; a first gate line disposed on the first substrate andwhich transmits a first gate signal; a second gate line disposed on thefirst substrate and which transmits a second gate signal; a first dataline disposed on the first substrate; a second data line disposed on thefirst substrate; a third data line disposed on the first substrate; afirst switching element connected to the first gate line and the firstdata line; a second switching element connected to the first gate lineand the second data line; a third switching element connected to thesecond gate line and the second data line; a fourth switching elementconnected to the second gate line and the third data line; a first pixelelectrode connected to the first switching element; a second pixelelectrode connected to the second switching element and separated fromthe first pixel electrode; a third pixel electrode connected to thethird switching element; and a fourth pixel electrode connected to thefourth switching element and separated from the third pixel electrode,wherein the first pixel electrode and the second pixel electrode form afirst liquid crystal capacitor, and the third pixel electrode and thefourth pixel electrode form a second liquid crystal capacitor.
 2. Theliquid crystal display of claim 1, wherein the first pixel electrodeincludes first branches, the second pixel electrode includes secondbranches, the first branches of the first pixel electrode and the secondbranches of the second pixel electrode are alternately disposed on thefirst substrate, the third pixel electrode includes third branches, thefourth pixel electrode includes fourth branches, and the third branchesof the third pixel electrode and the fourth branches of the fourth pixelelectrode are alternately disposed on the first substrate.
 3. The liquidcrystal display of claim 2, wherein when the first gate line receives agate-on signal, the first pixel electrode receives a first data voltagefrom the first data line and the second pixel electrode receives asecond data voltage from the second data line, and a polarity of thefirst data voltage with respect to a reference voltage is opposite to apolarity of the second data voltage with respect to the referencevoltage.
 4. The liquid crystal display of claim 3, wherein when thesecond gate line receives a gate-on signal, the third pixel electrodereceives a third data voltage from the second data line and the fourthpixel electrode receives a fourth data voltage from the third data line,a polarity of the third data voltage with respect to the referencevoltage is opposite to a polarity of the fourth data voltage withrespect to the reference voltage, and the polarity of the second datavoltage with respect to the reference voltage is the same as thepolarity of the third data voltage with respect to the referencevoltage.
 5. The liquid crystal display of claim 2, further comprising: athird gate line disposed on the first substrate; a fourth gate linedisposed on the first substrate; a fourth data line disposed on thefirst substrate; a fifth data line disposed on the first substrate; asixth data line disposed on the first substrate; a fifth switchingelement connected to the third gate line and the fourth data line; asixth switching element connected to the third gate line and the fifthdata line; a seventh switching element connected to the fourth gate lineand the fifth data line; an eighth switching element connected to thefourth gate line and the sixth data line; a fifth pixel electrodeconnected to the fifth switching element; a sixth pixel electrodeconnected to the sixth switching element and separated from the fifthpixel electrode; a seventh pixel electrode connected to the seventhswitching element; and a eighth pixel electrode connected to the eighthswitching element and separated from the seventh pixel electrode,wherein the third gate line is connected to the first gate line andtransmits the first gate signal, the fourth gate line is connected tothe second gate line and transmits the second gate signal, the fifthpixel electrode and the sixth pixel electrode form a third liquidcrystal capacitor, and the seventh pixel electrode and the eighth pixelelectrode form a fourth liquid crystal capacitor.
 6. The liquid crystaldisplay of claim 5, wherein the first data line and the fourth data lineare disposed substantially adjacent to each other, the second data lineand the fifth data line are disposed substantially adjacent to eachother, and the third data line and the sixth data line are disposedsubstantially adjacent to each other.
 7. The liquid crystal display ofclaim 6, wherein the fifth pixel electrode includes fifth branches, thesixth pixel electrode includes sixth branches, the fifth branches of thefifth pixel electrode and the sixth branches of the sixth pixelelectrode are alternately disposed on the first substrate, the seventhpixel electrode includes seventh branches, the eighth pixel electrodeincludes eighth branches, and the seventh branches of the seventh pixelelectrode and the eighth branches of the eighth pixel electrode arealternately disposed on the first substrate.
 8. The liquid crystaldisplay of claim 1, further comprising: a first storage capacitorconnected to the first switching element; and a second storage capacitorconnected to the second switching element and separated from the firststorage capacitor.
 9. The liquid crystal display of claim 1, furthercomprising: a capacitive electrode connected to the first pixelelectrode and which overlaps the second pixel electrode with aninsulating layer disposed therebetween, wherein the capacitive electrodeand the second pixel electrode form a storage capacitor.
 10. A liquidcrystal display comprising: a first substrate; a second substratedisposed opposite the first substrate; a liquid crystal layer interposedbetween the first and second substrates and including liquid crystalmolecules; a first gate line disposed on the first substrate and whichtransmits a first gate signal; a second gate line disposed on the firstsubstrate and which transmits a second gate signal; a third gate linedisposed on the first substrate and which transmits a third gate signal;a first data line disposed on the first substrate; a second data linedisposed on the first substrate; a first switching element connected tothe first gate line and the first data line; a second switching elementconnected to the second gate line and the second data line; a thirdswitching element connected to the third gate line and an outputterminal of the second switching element; and a first pixel electrodeconnected to the first switching element and a second pixel electrodeconnected to the second switching element and separated from the firstpixel electrode, wherein an input terminal of the third switchingelement is connected to the output terminal of the second switchingelement, an output terminal of the third switching element is connectedto the second pixel electrode, and the first pixel electrode and thesecond pixel electrode form a first liquid crystal capacitor.
 11. Theliquid crystal display of claim 10, wherein the first pixel electrodeincludes first branches, the second pixel electrodes includes secondbranches, and the first branches of the first pixel electrode and thesecond branches of the second pixel electrode are alternately disposedon the first substrate.
 12. The liquid crystal display of claim 11,wherein when the first gate line receives a gate-on signal, the firstpixel electrode receives a first data voltage from the first data lineand the third pixel electrode receives a second data voltage from thesecond data line, when the second gate line receives the gate-on signal,the second pixel electrode receives a third data voltage from the seconddata line and the fourth pixel electrode receives a fourth data voltagefrom the third data line, the first data voltage and the second datavoltage have different polarities, the second data voltage and the thirddata voltage have different polarities, and when the third gate linereceives the gate on signal, the second data voltage is transmittedthrough the third switching element.
 13. The liquid crystal display ofclaim 10, further comprising: a fourth gate line disposed on the firstsubstrate; a fifth gate line disposed on the first substrate; a sixthgate line disposed on the first substrate; a third data line disposed onthe first substrate; a fourth data line disposed on the first substrate;a fourth switching element connected to the fourth gate line and thethird data line; a fifth switching element connected to the fifth gateline and the fourth data line; a sixth switching element connected tothe sixth gate line and an output terminal of the fifth switchingelement; and a third pixel electrode connected to the fourth switchingelement and a fourth pixel electrode connected to the fifth switchingelement and separated from the third pixel electrode, wherein the fourthgate line is connected to the first gate line and transmits the firstgate signal, the fifth gate line is connected to the second gate lineand transmits the second gate signal, the sixth gate line is connectedto the third gate line and transmits the third gate signal, and thethird pixel electrode and the fourth pixel electrode form a secondliquid crystal capacitor.
 14. The liquid crystal display of claim 13,wherein the first data line and the third data line are disposedsubstantially adjacent to each other, and the second data line and thefourth data line are disposed substantially adjacent to each other. 15.The liquid crystal display of claim 14, wherein the third pixelelectrode includes third branches, the fourth pixel electrode includesfourth branches, and the third branches of the third pixel electrode andthe fourth branches of the fourth pixel electrode are alternatelydisposed on the first substrate.
 16. A liquid crystal displaycomprising: a first substrate; a second substrate disposed opposite thefirst substrate; a liquid crystal layer interposed between the first andsecond substrates and including liquid crystal molecules; a first gateline disposed on the first substrate and which transmits a first gatesignal; a second gate line disposed on the first substrate and whichtransmits a gate signal; a data line disposed on the first substrate; afirst switching element connected to the first gate line and the dataline; a second switching element connected to the second gate line andthe data line; a first pixel electrode connected to the first switchingelement; a second pixel electrode connected to the second switchingelement and separated from the first pixel electrode; and a step-upcapacitor including a first capacitive electrode and a second capacitiveelectrode connected to the first and second switching elements,respectively, and which overlap each other with an insulating layerdisposed therebetween, wherein the first pixel electrode and the secondpixel electrode form a first liquid crystal capacitor.
 17. The liquidcrystal display of claim 16, wherein the first pixel electrode includesfirst branches, the second pixel electrode includes second branches, andthe first branches of the first pixel electrode and the second branchesof the second pixel electrode are alternately disposed on the firstsubstrate.
 18. The liquid crystal display of claim 17, wherein when thefirst gate line receives a gate-on signal, the first pixel electrode andthe first capacitive electrode receive the first data voltage from thedata line, and when the second gate line receives the gate-on signal,the second pixel electrode and the second capacitive electrode receivethe second data voltage from the data line and voltages of the firstpixel electrode and the first capacitive electrode are substantiallyincreased.
 19. The liquid crystal display of claim 16, furthercomprising: a third switching element including an input terminalconnected to the first gate line and an output terminal connected to thesecond pixel electrode and the second capacitive electrode, wherein theinput terminal of the third switching element receives a common voltage.20. The liquid crystal display of claim 19, wherein when the first gateline receives the gate-on signal, the second pixel electrode and thesecond capacitive electrode receive the common voltage through the thirdswitching element.